new plantuml-stdlib versions use README.md instead INFO; LICENSE update is missing

[kirchsth]

Based on the discussion Is it possible to create on each folder a Readme.md file? in plantuml/plantuml-stdlib the update process and templates have to be updated that the correct README.md file is created (instead of INFO).

The default version of the README.md looks like below:

---
name: c4
display_name: C4
description: 
author: 
version: 2.11.0
release: 
license: 
source: https://github.com/plantuml-stdlib/C4-PlantUML
origin: 
---

Information about the `C4` Standard Library.

Some of the fields are author:, license:, ... Based on that we should use the opportunity and update the LICENSE file too.